Small forward Thanasis Antetokounmpo, the Knicks’ 2014 second-round pick who was released during training camp, will sign a 10-day contract to claim their open roster spot and will join the club for Friday’s game against the Suns at the Garden.

Antetokounmpo, whose younger brother, Giannis, is a star for the Bucks, had been playing for the D-League Westchester Knicks, averaging 10.3 points, 4.4 rebounds and 1.3 blocks per game.

The defensive specialist, Antetokounmpo, 23, also played last season for Westchester after being selected 51st overall. The Knicks no longer held his NBA rights and any team could have signed him as a free agent.

Sources had told The Post the Knicks were waiting to use the roster spot only when faced with injuries. With Cleanthony Early out because of a gunshot wound to his knee, Lance Thomas coming off a knee sprain and Carmelo Anthony’s knee soreness, the Knicks had a need for a healthy wing defender who already knew the triangle offense. Jose Calderon’s groin strain, which forced him out of the lineup Thursday night, made the need for an extra body necessary.

It was a surprise move considering the Knicks had been evaluating sharpshooting guard Jimmer Fredette, also at Westchester, but did not deem point guard the priority right now. Sources also said the Knicks do not expect to have negotiations with the Hawks for point guard Jeff Teague. One report stated Atlanta did have some offers — not from the Knicks — for Teague.

Knicks coach Derek Fisher watched tape of Antetokounmpo’s D-League performances this season, but hadn’t been to a game.

“He’s doing things he’s capable of doing,’’ Fisher said. “With injuries and limited practice time, it’s important to have guys who are familiar with who they are and what we do. We’re looking forward to having him around.’’

Former 76ers guard Tony Wroten was considered another 10-day candidate, but fears about his triangle knowhow surfaced within the organization.

Knicks president Phil Jackson also owed Antetokunmpo, who bypassed a European contract before the 2014-15 season to stay with Westchester. The Knicks didn’t sign him despite open roster spots.

“At this time last year we had guys join us who are still with us,’’ Fisher said. “I’m sure he’s looking forward to taking that opportunity.’’

Former Westchester teammate Langston Galloway lived with the Greek native last season.

“I’m happy for him,’’ Galloway said. “You always need that energy for offense and defense. It’s a long season.’’

Calderon said he first injured his groin in Charlotte on Saturday, then felt it again against the Thunder — which is why he didn’t play the fourth quarter against Oklahoma City. Thursday was the first game Calderon missed this season after his injury-wracked first season in New York.

“With injuries, you can’t get into the guessing game,’’ Calderon said. “Right now it doesn’t seem major or significant. But we have to continue to monitor it, make sure when he’s back on the court, he’s back and it’s not day-to-day. Groin, hamstring, those injuries are hard to gauge.’’